Papers › Optimizing Test-Time Query Representations for Dense Retrieval

Optimizing Test-Time Query Representations for Dense Retrieval

25 May 2022arXiv:2205.12680archive 2025-07-28

Mujeen Sung, Jungsoo Park, Jaewoo Kang, Danqi Chen, Jinhyuk Lee

Recent developments of dense retrieval rely on quality representations of queries and contexts from pre-trained query and context encoders. In this paper, we introduce TOUR (Test-Time Optimization of Query Representations), which further optimizes instance-level query representations guided by signals from test-time retrieval results. We leverage a cross-encoder re-ranker to provide fine-grained pseudo labels over retrieval results and iteratively optimize query representations with gradient descent. Our theoretical analysis reveals that TOUR can be viewed as a generalization of the classical Rocchio algorithm for pseudo relevance feedback, and we present two variants that leverage pseudo-labels as hard binary or soft continuous labels. We first apply TOUR on phrase retrieval with our proposed phrase re-ranker, and also evaluate its effectiveness on passage retrieval with an off-the-shelf re-ranker. TOUR greatly improves end-to-end open-domain question answering accuracy, as well as passage retrieval performance. TOUR also consistently improves direct re-ranking by up to 2.0% while running 1.3-2.4x faster with an efficient implementation.

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annotate_phrase_vecs dmis-lab/tour/run_tour_densephrases.py official repository ran · our draft was wrong Apache-2.0 (permissive) · b2500f60514bc88f · report
get_top_phrases_query_vec dmis-lab/tour/run_tour_densephrases.py official repository ran · our draft was wrong Apache-2.0 (permissive) · 761193604ffd421f · report
load_json dmis-lab/tour/cross_encoder.py official repository ran · our draft was wrong Apache-2.0 (permissive) · 8d6173f6bbbf118a · report
sort_based_on_index dmis-lab/tour/cross_encoder.py official repository ran · violated contract Apache-2.0 (permissive) · 7a2ec91f84e33d49 · report
update_query_vec dmis-lab/tour/run_tour_densephrases.py official repository ran · fixture could not drive it Apache-2.0 (permissive) · cefc3944c11d3826 · report
to_fp16 dmis-lab/tour/cross_encoder.py official repository unverified Apache-2.0 (permissive) · df86542c150c270b · report

Tasks

Contrastive LearningInformation RetrievalOpen-Domain Question AnsweringPassage RetrievalQuestion AnsweringRe-RankingRetrieval

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Contrastive Learning

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